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In vivo left ventricular assist induced coagulation derangements. Comparison of Sarns-3M and St. Jude Medical
J J Curtis1, C C Wagner-Mann, F A Mann
1Department of Surgery, School of Medicine, College of Veterinary Medicine, University of Missouri, Columbia, USA.
Insights
This study found that both Sarns-3M and St. Jude left ventricular assist (LVA) devices caused similar coagulation issues in calves over 96 hours. In vivo results did not support in vitro findings of hemolysis differences.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Hematology
Background:
- Centrifugal pumps are used in left ventricular assist (LVA) devices.
- Previous in vitro studies suggested differences in blood cell derangement between Sarns-3M and St. Jude Medical pumps.
- The in vivo effects of these pumps on hemostasis and hemolysis require further investigation.
Purpose of the Study:
- To compare the in vivo effects of 96-hour left ventricular assist (LVA) using Sarns-3M and St. Jude centrifugal pumps.
- To evaluate the impact of these devices on indexes of coagulopathy, hemolysis, and complement activation.
Main Methods:
- Two groups of calves (n=5 each) underwent 96-hour LVA with either Sarns-3M or St. Jude centrifugal pumps.
- Laboratory evaluations of coagulation, hemolysis, and complement activation were performed at multiple time points.
- Parameters assessed included platelet counts, activated clotting time, prothrombin time, activated partial thromboplastin time, lactate dehydrogenase, plasma free hemoglobin, and complement fraction C5a.
Main Results:
- Platelet counts decreased significantly in both groups by 24 hours.
- Prothrombin time and activated partial thromboplastin time showed transient increases, with the latter being significant for the St. Jude device.
- Complement fraction C5a levels increased early in LVA but returned to baseline; no significant differences were observed between pump types for any parameter.
Conclusions:
- Both Sarns-3M and St. Jude LVA devices caused coagulation derangement in calves over 96 hours.
- Neither pump demonstrated a significant advantage regarding coagulation and complement parameters in vivo.
- In vitro observed differences in hemolysis were not evidenced in vivo, suggesting in vitro findings may not translate to clinical outcomes.
Abstract:
An in vitro comparison of centrifugal pumping systems manufactured by Sarns-3M and St. Jude Medical revealed a difference in blood cell derangement. The purpose of this study was to compare in vivo the effects of 96 hr of left ventricular assist (LVA) on indexes of coagulopathy, hemolysis, and complement activation. Two groups of calves (each: n = 5) were instrumented with identical left atrial to thoracic aorta centrifugal pumping circuits using either Sarns-3M or St. Jude centrifugal pumps. Laboratory evaluations were performed pre-assist and at 1, 4, 24, 48, 72, and 96 hr during LVA. Platelet counts dropped significantly by 24 hr (Sarns-3M: 28%; St. Jude: 30%); no significant change in function was noted. Activated clotting time increased slightly (p > 0.05). Prothrombin time increased at 4 and 24 hr of LVA, returning to baseline by 96 hr (p < 0.05). Activated partial thromboplastin time increased with the St. Jude device from 24 to 96 hr on LVA (p < 0.05); the increase with the Sarns-3M device never reached significance. No significant changes in lactate dehydrogenase or plasma free hemoglobin were detected. Complement fraction C5a rose by 1 hr of LVA (p < 0.05), peaking at 4 hr and returning to baseline by 96 hr with both pumps. No significant difference was detected between pump groups for any of the parameters. It was concluded that 1) 96 hr Sarns-3M and St. Jude LVA caused coagulation derangement in calves, 2) neither pump demonstrated an advantage regarding coagulation and complement parameters, 3) hemolysis observed with the Sarns-3M pump in vitro was not evidenced in vivo, and 4) in vitro evidenced centrifugal pump differences may not be realized in vivo.